
Chevrolet Blazer Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
13557845) - 2020 - CRC - 3/24/20
118 Instruments and Controls
accessories are operating in the
vehicle and the engine is left idling
for an extended period. This
condition is normal since the
charging system is not able to
provide full power at engine idle. As
engine speeds are increased, this
condition should correct itself as
higher engine speeds allow the
charging system to create maximum
power.
The vehicle can only be driven for a
short time with the readings outside
the normal operating range. If the
vehicle must be driven, turn off all
accessories, such as the radio and
air conditioner, and unplug all
chargers and accessories.
Readings outside the normal
operating range indicate a possible
problem in the electrical system.
Have the vehicle serviced as soon
as possible.Seat Belt Reminders
Driver Seat Belt Reminder
Light
There is a driver seat belt reminder
light on the instrument cluster.
When the vehicle is started, this
light flashes and a chime may come
on to remind the driver to fasten
their seat belt. Then the light stays
on solid until the belt is buckled.
This cycle may continue several
times if the driver remains or
becomes unbuckled while the
vehicle is moving.
If the driver seat belt is buckled,
neither the light nor the chime
comes on.
Passenger Seat Belt Reminder
Light
There is a passenger seat belt
reminder light near the passenger
airbag status indicator. See
Passenger Sensing System066.
When the vehicle is started, this
light flashes and a chime may come
on to remind passengers to fasten
their seat belt. Then the light stays
on solid until the belt is buckled.
This cycle continues several times if
the passenger remains or becomes
unbuckled while the vehicle is
moving.
If the passenger seat belt is
buckled, neither the chime nor the
light comes on.
The front passenger seat belt
reminder light and chime may turn
on if an object is put on the seat

Chevrolet Blazer Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
13557845) - 2020 - CRC - 3/24/20
120 Instruments and Controls
passenger sensing system has
turned off the front outboard
passenger frontal airbag.
If, after several seconds, both status
indicator lights remain on, or if there
are no lights at all, there may be a
problem with the lights or the
passenger sensing system. See
your dealer for service.
{Warning
If the airbag readiness light ever
comes on and stays on, it means
that something may be wrong
with the airbag system. To help
avoid injury to yourself or others,
have the vehicle serviced right
away. SeeAirbag Readiness
Light 0119 for more information,
including important safety
information.
Charging System Light
The charging system light comes on
briefly when the ignition is turned
on, but the engine is not running, as
a check to show the light is working.
The light turns off when the engine
is started. If it does not, have the
vehicle serviced by your dealer.
If the light stays on, or comes on
while driving, there may be a
problem with the electrical charging
system. Have it checked by your
dealer. Driving while this light is on
could drain the battery.
When this light comes on, the Driver
Information Center (DIC) also
displays a message.
If a short distance must be driven
with the light on, be sure to turn off
all accessories, such as the radio
and air conditioner.
Malfunction Indicator
Lamp (Check Engine
Light)
This light is part of the vehicle’s
emission control on-board
diagnostic system. If this light is on
while the engine is running, a
malfunction has been detected and
the vehicle may require service. The
light should come on to show that it
is working when the ignition is in
Service Mode. See Ignition
Positions 0178.
Malfunctions are often indicated by
the system before any problem is
noticeable. Being aware of the light
and seeking service promptly when
it comes on may prevent damage.

Chevrolet Blazer Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
13557845) - 2020 - CRC - 3/24/20
Climate Controls 157
Driver and Passenger
Temperature Controls :The
temperature can be adjusted
separately for the driver and the
passenger. Turn the knob clockwise
or counterclockwise to increase or
decrease the driver or passenger
temperature setting.
SYNC : Press to link all passenger
temperature settings to the driver
setting. The SYNC indicator light will
turn on. When the passenger
settings are adjusted, the SYNC
indicator light turns off.
Manual Operation
O: Press to turn the fan off or on.
When off is selected, the system will
prevent air from flowing into the
cabin. If on is selected, or any other
button is pressed, the climate
control system will turn on and
return to delivering airflow as set.
The temperature control and air
delivery mode can still be adjusted.
^: Press to increase or decrease
the fan speed. The fan speed
setting appears on the main display.
Pressing any airflow mode button cancels automatic fan control and
the fan is controlled manually. Press
AUTO to return to automatic
operation.
Air Delivery Mode Controls :
Press
X,Y, or[to change the
direction of the airflow. Any
combination of the three buttons
can be selected. The indicator light
in the button will turn on. The
current mode appears in the display.
Pressing either button cancels
automatic air delivery control and
the direction of the airflow is
controlled manually. Press AUTO to
return to automatic operation.
To change the current mode, select
one or more of the following modes:
X: Clears the windows of fog or
moisture. Air is directed to the
windshield.
Y: Air is directed to the instrument
panel outlets.
[: Air is directed to the floor
outlets.
0MAX : Air is directed to the
windshield, the fan runs at a higher
speed, and the temperature of the
air is increased if not already at
maximum. This mode overrides the
previous mode selected and clears
fog or frost from the windshield
more quickly. When the button is
pressed again, the system returns
to the previous mode setting and
fan speed.
For best results, clear all snow and
ice from the windshield before
defrosting and do not use
recirculation.
A/C : Press to turn the air
conditioning system on or off. If the
climate control system is turned off
or the outside temperature falls
below freezing, the air conditioner
will not run.
Pressing this button cancels
automatic air conditioning and turns
off the air conditioner. Press AUTO
to return to automatic operation and
the air conditioner runs
automatically as needed. When the
indicator light is on, the air
conditioner runs automatically to

Chevrolet Blazer Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
13557845) - 2020 - CRC - 3/24/20
158 Climate Controls
cool the air inside the vehicle or to
dry the air needed to defog the
windshield faster.
@:Press to turn on recirculation.
An indicator light comes on. Air is
recirculated to quickly cool the
inside of the vehicle or to reduce the
entry of outside air and odors.
If selected during cool or cold
weather, the windshield and
windows may fog. Turn off
recirculation to help clear the
windshield and windows.
Auto Defog : The climate control
system may have a sensor to
automatically detect high humidity
inside the vehicle. When high
humidity is detected, the climate
control system may adjust to
outside air supply and turn on the
air conditioner. The fan speed may
slightly increase to help prevent
fogging. If the climate control
system does not detect possible
window fogging, it returns to normal
operation. To turn Auto Defog off or on, see
“Climate and Air Quality”
under
Vehicle Personalization 0137.Rear Window Defogger
=:Press to turn the rear window
defogger on or off. An indicator light
on the button comes on to show that
the rear window defogger is on. The
rear window defogger only works
when the ignition is on. The
defogger turns off when the ignition
is off or in ACC/ACCESSORY.
The rear window defogger can be
set to automatic operation. See
“Climate and Air Quality” under
Vehicle Personalization 0137.
When Auto Rear Defog is selected,
the rear window defogger turns on
automatically when the interior
temperature is cold and the outside
temperature is about 7 °C (44 °F)
and below. The auto rear defogger
turns off automatically.
If the vehicle is equipped with
heated outside mirrors, they turn on
when the rear window defogger button is on and help to clear fog or
frost from the surface of the mirror.
See
Heated Mirrors 031.Caution
Do not try to clear frost or other
material from the inside of the
front windshield and rear window
with a razor blade or anything
else that is sharp. This may
damage the rear window
defogger grid and affect the
radio's ability to pick up stations
clearly. The repairs would not be
covered by the vehicle warranty.
LorM:If equipped, pressLorMto heat the driver or passenger seat.
See Heated and Ventilated Front
Seats 047.
{orC:If equipped, press{orCto ventilate the driver or passenger
seat. See Heated and Ventilated
Front Seats 047.

Chevrolet Blazer Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
13557845) - 2020 - CRC - 3/24/20
160 Climate Controls
.Keep the path under all seats
clear of objects to help circulate
the air inside the vehicle more
effectively.
. If fogging reoccurs while in vent
or in a combination mode with
mild temperature throughout the
vehicle, turn on the air
conditioner to reduce windshield
fogging.Maintenance
Passenger Compartment
Air Filter
The filter reduces dust, pollen, and
other airborne irritants from outside
air that is pulled into the vehicle.
The filter should be replaced as part
of routine scheduled maintenance.
See Maintenance Schedule 0339.
See your dealer regarding
replacement of the filter.
Service
All vehicles have a label underhood
that identifies the refrigerant used in
the vehicle. The refrigerant system
should only be serviced by trained
and certified technicians. The air
conditioning evaporator should
never be repaired or replaced by
one from a salvage vehicle.
It should only be replaced by a new
evaporator to ensure proper and
safe operation. During service, all refrigerants
should be reclaimed with proper
equipment. Venting refrigerants
directly to the atmosphere is harmful
to the environment and may also
create unsafe conditions based on
inhalation, combustion, frostbite,
or other health-based concerns.
The air conditioning system requires
periodic maintenance. See
Maintenance Schedule
0339.